ML20011E841
| ML20011E841 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 02/13/1990 |
| From: | Vaughn H GILBERT/COMMONWEALTH, INC. (FORMERLY GILBERT ASSOCIAT |
| To: | Murley T Office of Nuclear Reactor Regulation |
| References | |
| REF-PT21-90-026-000 PT21-90-026-000, PT21-90-26, NUDOCS 9002220573 | |
| Download: ML20011E841 (2) | |
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' Gilbert / Commonwealth, Inc. ensnemina consuitants P.O. Box 1498, Reading. PA 1960M498/ Telephone 215 775 2600, Cable Gilasoc/ Telex 836 431 H. E. VAUGHN Vice President & General Manager Quality Assurance Division February 13,1990 United States Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D.C. 20555 Attention: Mr. T. E. Murley, Director Ret Reportable Event Chilled Water System This documents my report by telephone under the provialons of 10CFR 21 on February 9,1990 at approximately 2:20 p.m.
Individual Who Reported:
Mr. H. E..Vaughn, Vice Fresident and General Manager, Quality Assurance Division, Gilbert /Com monwealth, Inc.
)
l Facility Involved:
V.C. Summer Nuclear Station (Docket 50-395) operated by South Carolina Electric &
Gas Company.
1 Activity involved:
Design analysis chilled water system J
Nature of Defect:
i The design basis of the chilled water system considered the worst case condition to be's q
high energy line break with single failure of one chiller during the winter season. At
- that time, the service water flow to the chiller is manually throttled to maintain a 65 F to 95'F service water outlet temperature.
The preliminary results of our evaluation Indicate that the above system set-up could potentially cause a chiller trip (hlgh compressor motor temperature or high condenser pressure) due to excessive steam heat load (HELB) while operating with throttled service water flow. This would require local manual restart of the chiller and opening of the service water valve to increase the flow.
This manual action may not be practical due to the steam environment.
This can result in the chilled water temperature rising which has the potential for compromising the operability of safety related equipment.
9002220573 900213 gDR : ADOCK 05000395 PDC Green Hills. Readmg. PA 196031490. (2156 7752600 525 Lancaster Avenue. Readmg PA 19603-1498 (?i5) 775-2600 g
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aQL9ERT/COMWONW1 ALTH,INC..PO Bon less, h.admg PA 198G1/10( !15 TF$2600/ Cap GWsoclTWes $X431 Mr. T. E. Murley, Director United States Nuclear Regulatory Commission February 13,1990 Page 2-Also, guidance on temporary operation (until plant modifications were to be installed) was provided to the utility during the initial start-up phase, to alleviate temperature concerns in the electrical switchgear room served by the idle train. This guidance did not adequately define the durational limitations of the recommended temporary operation of the chillers.
Date information Obtained:
The Quality Assurance Division General Manager was informed on February 9,1990 of the reportability of this item.
This situation has been reviewed for other plants which G/C was the A/B of record, and it has been determined that at this time this situation appears to be unique to V.C.
Summer Nuclear Station, however, evaluation of one specific area has not been completed for Crystal River Unit 3 (50-302). Florida Power Corporation was informed of this evaluation on February 9,1990.
Corrective Action:
V.C. Summer Nuclear Station has been placed in a safe condition by issuing revised guidelines for minimum chiller load operation and by selectively isolating cooling coils to remove them from the potential of a steam environment.
Permanent modifications will be evaluated and recommended to SCE&G.
G/C will issue an internal Design Bulletin to alert all engineers to this situation.
if you require any further information, please call me at (215) 775-2600, extension 4548.
Very truly yo.m
)rs, S
- h.I D A H. E. Vauglitr-
~Y_ --
N Vice President & General Manager Quality Assurance Division HEV: tin cct T. E. Murley (NRC) (2)
C. D. Williams Document Management Branch (NRC)
W. K. Burkhart R. B. Clary (SCE&G)
W. E. Meek A. R. Koon, Jr. (SCE&G)
K. E. Nodland (2)
R. E. Vaughn
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